Teemeister: The small problem with that specific notion is... it's not legal. No company in their right mind is going to purposefully release free fully-functional trial versions to P2P networks.
Of course, companies do release non-fully-functional free trial versions... they're called "demos".
No, I'm talking the way other rentals are handled now... you plunk down $3 and get to play a full version of a game for a week that the rental place legally acquired. It works for console games... why not for PC games?
Well, actually, I know why in the past... it used to be you could pirate PC games without a lot of fuss, but not console games (since they were cartridges). But seeing as how console games and movies are almost all CDs or DVDs now anyway, it seems like less of an issue there.
One downside is that rental versions of games/software would *have* to be DRMed in some fashion, otherwise a customer could just do a full-install, return the software CD/DVD, and dub himself one bit of software richer for $3. Yes, you can rip rental movies DVDs too, for instance, but the idea of using software without a CD is a "normal function", as it were... ripping a DVD isn't.
Peace & Luv, Liz